succeed without changing the uid and gid, like FreeBSD.
incorrect, as it failed to update the last-changed time and reset
special permission bits, as POSIX requires.
+ "chown : file", "chown '' file", and "chgrp '' file" now succeed
+ without changing the uid or gid, instead of reporting an error.
+
Do not report an error if the owner or group of a
recursively-encountered symbolic link cannot be updated because
the file system does not support it.